Tony Scott, the director behind a raft of action blockbusters including Top Gun and Beverly Hills Cop II, has leapt to his death from a harbour bridge in Los Angeles, shocking Hollywood.

The American broadcaster ABC News reported last night that the British-born director and producer had been diagnosed with inoperable brain cancer – quoting a source close to the filmmaker. Born in North Shields, Mr Scott was the brother of the director Ridley Scott. He was seen by several witnesses jumping from a bridge spanning Los Angeles harbour at about 12.30pm on Sunday. His body was retrieved from the waters by police divers a few hours later.

The witnesses said they saw Mr Scott, who was 68, stopping his car, a Toyota Prius, in the middle of the bridge, scaling a high fence and then throwing himself off apparently without any hesitation. The 6,060ft Vincent Thomas Bridge rises to 185 feet at its highest point and has been featured in Hollywood films such as The Fast and the Furious. It is a notorious spot in Los Angeles for suicide jumpers.

The Los Angeles Coroner's Office confirmed that his death was being treated as a suicide. "There's nothing to indicate it is anything else at this time," said Lt Joe Bale, although final word on cause of death will not be released until completion of an autopsy.

Hollywood A-listers paid tribute to the man noted for his fast-paced editing style and for hits with Top Gun, Days of Thunder, Crimson Tide, True Romance and Enemy of the State. Earlier this year, Mr Scott teamed up with Ridley to produce the anticipated Alien prequel, Prometheus.

Tony and Ridley founded a production company together called Scott Free Productions. Tony Scott's repertoire also stretched into countless commercials for television as well as the development of TV dramas including the The Good Wife and Numb3rs, both originally made for the CBS network. Of the two brothers, it was Ridley, whose credits include Alien and Gladiator, who received the most critical acclaim, including a series of nominations at the Oscars.

Tony, who specialised in high-grossing, high-octane films such as his 2000 hit Unstoppable, was never nominated. He was nonetheless a fixture in the Hollywood community and, with his trademark cigar and frayed baseball cap, was widely liked.

There was no confirmation by the Coroner's Office of reports in the Los Angeles Times that police found a note with contact details, including the phone number of his wife, inside the car and that investigators had also located a suicide note in his office. Nor were the contents of the alleged note disclosed. Simon Halls, a spokesman for the Scotts said the family asked "that their privacy be respected at this time".

The tributes came quickly. The actor Adam Goldberg, who worked with Scott on Deja Vu, said: "Tony Scott was one of the, if not the, warmest and most generous directors for whom I've ever worked. I'll miss you man." The actress Keira Knightley, who starred in his 2005 film Domino, called him "one of the most extraordinary, imaginative men I ever worked with". The Top Gun actor Val Kilmer said: "RIP Tony. You were the kindest film director I ever worked for. You will be missed." Director Ron Howard said: "No more Tony Scott movies. Tragic day." Robert Rodriguez, director of Sin City and Desperado added: "Tony Scott. Damn. Great knowing you, buddy. Thanks for the inspiration, advice, encouragement, and the decades of great entertainment."

Scott had recently completed filming on a suspense feature called Out of the Furnace. Due out next spring, it features the actor Christian Bale playing the role of an ex-prison inmate.

The police in Los Angeles were alerted to Mr Scott's apparent suicide thanks to witnesses who called the 911 emergency number instantly to report seeing him fall into the water. The bridge links San Pedro in Los Angeles with Terminal Island.